FMU Variable Editor — GUI¶

The FMU Variable Editor provides a spreadsheet-like interface to inspect and edit FMU variables (names and descriptions) as well as simulation experiment settings — without using the command line.

Launching the Interface¶

fmueditor

Or from the FMU Toolbox Launcher, click FMU Variables Editor.

Interface Overview¶

The interface is organized into the following areas:

Loading an FMU¶

Drag and drop a .fmu file onto the drop zone in the top-left corner.

Once loaded, the interface displays:

• FMU name (bold title)
• Generator Tool and Generation Date
• Start Time and Stop Time (editable)
• Preferred Step Size (read-only)
• Variable count

Variable Table¶

The table lists all variables defined in the FMU's modelDescription.xml:

Causality Icons¶

Each variable is tagged with a color-coded icon:

Editing Variables¶

• Rename a variable: double-click on the Name cell and type the new name.
• Edit a description: double-click on the Description cell.
• Modified values are highlighted in orange to indicate unsaved changes.

Sorting and Filtering¶

• Sort: click any column header to sort ascending/descending.
• Filter: type in the filter bar to instantly filter variables across all columns (name, causality, type, description).

Editing Experiment Settings¶

The Start Time and Stop Time fields in the top-right area are editable:

• Modify the values directly in the text fields.
• Changes will be written into the DefaultExperiment element of the modelDescription.xml when saving.

Saving the Modified FMU¶

1. Click Save modified FMU as…
2. Choose a filename and location
3. The new FMU is created with all your modifications applied

Only modified variables and experiment settings are written — unchanged variables pass through as-is.

Unsaved Changes Detection¶

If you close the editor or load a new FMU while there are unsaved modifications, a confirmation dialog will appear asking whether you really want to discard your changes.

Typical Workflow¶

Rename Variables in Bulk¶

1. Load the FMU
2. Use the filter bar to find variables (e.g., type Motor)
3. Double-click each Name cell to rename
4. Save the modified FMU

Add or Edit Descriptions¶

1. Load the FMU
2. Sort by Causality to group inputs, outputs, etc.
3. Double-click Description cells to add or update documentation
4. Save

Adjust Simulation Timing¶

1. Load the FMU
2. Edit Start Time and/or Stop Time in the top-right panel
3. Save

Keyboard Shortcuts¶